Chapter 12 Accessing Databases Getting Started FAQs Whats

Chapter 12 Accessing Databases

Getting Started • FAQs: – What’s a database? – Do I need database software? – How would I create my own database? – Can I really create databases with spreadsheet software? – What about databases on the Web? Practical PC 6 th Edition Chapter 12 2

What’s a database? • A database is a collection of data • Structured databases contain information that is organized as fields, records, and files – A field contains a single piece of information – A record contains fields of information about a single entity in the database – A group of similarly structured records form a file • A relational database allows you to store information for two or more different types of records and form a link between them – Each record type is stored in a table • For example, a video store database may include a table of customers and a table of movies • When a customer checks out a movie, a link is made between the two tables Practical PC 6 th Edition Chapter 12 3

What’s a database? Practical PC 6 th Edition Chapter 12 4

Do I need database software? • Database software provides a set of tools to enter and update information in fields – Also called a database management system – You can enter, delete, sort, and search for records – You might access a product database when shopping online or a bank database at an ATM • Database software offers a wealth of data management capabilities – Requires a substantial learning commitment – For simple files, you may be able to use My. Database, File. Maker Pro, and Open. Office Base – You can also use spreadsheet software for simple databases Practical PC 6 th Edition Chapter 12 5

Do I need database software? Practical PC 6 th Edition Chapter 12 6

How would I create my own database? • Creating a database consists of two tasks: – Creating the file structure to hold the data – Adding the data • A file structure is a specification for the database fields and their characteristics – You’ll need to assign a name to each field – You may also need to specify the data type and maximum field length • You then enter the data carefully and consistently – Be consistent with symbols, capitalization, categories, and abbreviations – Compare onscreen data against the original documents Practical PC 6 th Edition Chapter 12 7

How would I create my own database? Practical PC 6 th Edition Chapter 12 8

Can I really create databases with spreadsheet software? • You can use spreadsheet software to maintain files of information • You cannot use it to join files or tables together to create a relational database • You can use the Form View feature in spreadsheet software to view each row as a “card” containing a series of fields • You can also filter the data, which is more complicated, but useful for creating reports that show only selected data Practical PC 6 th Edition Chapter 12 9

Can I really create databases with spreadsheet software? Practical PC 6 th Edition Chapter 12 10

What about databases on the Web? • You’ll find many databases on the Web – Look up your old roommate in a phone-book-style database – Look up flights in a database of flight schedules – Check the value of your car in a digital “Blue Book” • When you use a browser to access databases on the Web, you’ll typically enter a query using an HTML form Practical PC 6 th Edition Chapter 12 11

What about databases on the Web? • You can also add data to an online database, a process that typically takes place when you register for an account at a Web site or when you check out from an e-commerce site Practical PC 6 th Edition Chapter 12 12

Hardware: Tracking Devices • Real-time locating systems are similar to baby monitors, and can keep an eye on children and pets • Tracking device transmits signals to nearby base station • Alerts tracker when trackee moves outside a designated area Practical PC 6 th Edition Chapter 12 13

Hardware: Tracking Devices • Mobile locating tracks the position of a cellular device based on its distance from cell towers • Accuracy varies with number of towers and type of antenna Practical PC 6 th Edition Chapter 12 14

Hardware: Tracking Devices • GPS (Global Positioning System) technology is more accurate than cellular triangulation – Includes smartphones, handheld GPSs and dash-mounted GPSs, and GPS loggers • GPS devices receive signals transmitted by a collection of earth-orbiting satellites – Must log on to four satellites to determine a location – Requires line of sight to the sky Practical PC 6 th Edition Chapter 12 15

Hardware: Tracking Devices Practical PC 6 th Edition Chapter 12 16

Hardware: Tracking Devices • RFID (Radio Frequency Identification) is not location aware, and only transmits identification information • An RFID tag is composed of a tiny read-only memory chip and transmitter incorporated on a flexible backing – Stores a unique number – Can be read from a distance Practical PC 6 th Edition Chapter 12 17

Who owns information about me? • What do you think? – Can you identify an actual incident when you discovered that data about you had been distributed without your approval? – Do you accurately fill out questionnaires that you encounter on the Web? – Do you think that you have the right to be consulted before anyone distributes information about you? Practical PC 6 th Edition Chapter 12 18